UMTS/HSPA+ Module Series
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3.6. Turn Off
The following procedures can be used to turn off the module.
3.6.1. Turn off the Module with PWRKEY
Driving the PWRKEY to a low-level voltage for at least 650 ms, then the module will execute power-down
procedure after the PWRKEY is released. The timing of turning off the module is illustrated in the following
figure.
Figure 12: Timing of Turning off Module
3.6.2. Turn off the Module with AT Command
It is safe to use
AT+QPOWD
to turn off the module, which is equal to turn off the module via PWRKEY
Pin.
1. Make sure that VBAT is stable before pulling down PWRKEY pin. It is recommended that the time
difference between powering up VBAT and pulling down PWRKEY pin is no less than 30 ms.
2. PWRKEY can be
pulled down directly to GND with a recommended 4.7 kΩ resistor if module needs
to be powered on automatically and shutdown is not needed.
NOTE